Combining Satellite and Ground-Based Ceilometer Data over the U.S. to Improve Cloud Ceiling Estimates away from Surface Stations

Flight planners and pilots require cloud ceiling information to conduct safe and efficient operations. Low visibility due to the presence of low cloud ceilings at airports can disrupt departures and arrivals causing delays and cancellations leading to financial loss to private and commercial aviation. Overhead sky conditions are reasonably well observed at many airports using a combination of human and ground-based sensor measurements, including ceilometers. Away from these stations at smaller airports and other areas where such observations are not available, cloud ceiling and visibility are not well known, further complicating small aircraft operations, including helicopters and airborne medical and rescue operations. To better address the low ceiling hazard to aviation, a hybrid approach is taken that uses satellite data to extend cloud ceiling information contained in surface station observations to wider areas. Near real-time correlative information between satellite cloud height observations and cloud ceiling information at surface stations are developed with the local relationships applied to satellite observations in surrounding areas and between stations using distance-weighted interpolation and extrapolation methods. The initial method is developed and tested using daytime observations over the U.S. from GOES-16 and automated surface station data. The goal is to utilize the direct observations of cloud ceiling from the relatively sparse surface station network to better constrain the satellite sensitivity to cloud height, cloud layering and thickness. This will improve satellite cloud ceiling estimates at high spatial and temporal resolution both in the immediate vicinity of, and well away from, surface stations. The approach exploits the synergy between advanced satellite imager data and ground-based observations over the U.S. and has potential to improve cloud ceiling analyses for the aviation community.